1. Field of the Invention
The present invention relates to non-latching electronic switches. More specifically, the present invention relates to a non-latching micro magnetic switch.
2. Background Art
Switches are typically electrically controlled two-state devices that open and close contacts to effect operation of devices in an electrical or optical circuit. Relays, for example, typically function as switches that activate or de-activate portions of electrical, optical, or other devices. Relays are commonly used in many applications including telecommunications, radio frequency (RF) communications, portable electronics, consumer and industrial electronics, aerospace, and other systems. More recently, optical switches implemented with relays (also referred to as “optical relays” or simply “relays” herein) have been used to switch optical signals (such as those in optical communication systems) from one path to another.
Although the earliest relays were mechanical or solid-state devices, recent developments in micro-electro-mechanical systems (MEMS) technologies and microelectronics manufacturing have made micro-electrostatic and micro-magnetic relays possible. Such micro-magnetic relays typically include an electromagnet that, when energized, causes a lever to make or break an electrical contact. When the magnet is de-energized, a spring or other mechanical force typically restores the lever to a quiescent position. Such relays typically exhibit a number of marked disadvantages, such as they are bulky in size, heavy, slow, expensive, and difficult to manufacture and integrate. Also, the spring required by conventional micro-magnetic relays may degrade or break over time.
Another micro-magnetic relay includes a permanent magnet and an electromagnet for generating a magnetic field that intermittently opposes the field generated by the permanent magnet. One drawback is that the relay must consume power from the electromagnet to maintain at least one of the output states. Moreover, the power required to generate the opposing field is significant, thus making the relay less desirable for use in space, portable electronics, and other applications that demand low power consumption.
Exemplary micro-magnetic switches are further described in international patent publications U.S. Pat. No. 6,469,602 (“the 602 patent”) that issued Oct. 22, 2002, entitled “Electronically Switching Latching Micro-magnetic Relay And Method of Operating Same,” and U.S. Pat. No. 6,496,612 (“the 612 patent”) that issued Dec. 17, 2002, entitled “Electronically Micro-magnetic latching switches and Method of Operating Same,” both to Ruan et al., are both incorporated by reference herein in their entireties.
Therefore, what is needed is a non-latching micro magnetic switch that can consume low power, be small, fast, and be easy to integrate. The switch can also be reliable, simple in design, low-cost, easy to manufacture, and useful in optical and/or electrical environments.